The present invention relates to ophthalmically useful compositions comprising a viscosity inducing component and an active pharmaceutical agent. In preferred embodiments, the pharmaceutically active agent can comprise a tyrosine kinase inhibitor (“TKI”) or other anti-angiogenesis agent. The invention also relates to methods for treating and/or preventing ocular conditions, such as anterior ocular conditions and posterior ocular conditions. In a preferred embodiment the present invention relates to extended release and sustained release therapeutic compositions comprising ophthalmically acceptable gels and liquid formulations comprising a viscosity inducing component and a tyrosine kinase inhibitor.
A pharmaceutical composition (synonymously a “composition”) is a formulation which contains at least one active ingredient (for example a tyrosine or serine kinase inhibitor capable of inhibiting angiogenesis (collectively, “TKIs” unless identified specifically or separately), or another anti-angiogenesis agent) together with a viscosity enhancing component. In certain embodiments the composition may also contain one or more excipients, such as a tonicity adjusting agent, an anti-oxidant, buffers, carriers, stabilizers, preservatives and/or bulking agents, and is suitable for administration to a patient to achieve a desired effect or result. The pharmaceutical compositions disclosed herein can have diagnostic, therapeutic, cosmetic and/or research utility in various species, such as for example in human patients or subjects.
A variety of ocular conditions involve a disease, ailment or condition which affects or involves the eye or one of the parts or regions of the eye and is characterized to a major or minor degree by angiogenesis (the formation of new blood vessels).
Broadly speaking, the eye includes the eyeball and the tissues and fluids which constitute the eyeball, the periocular muscles (such as the oblique and rectus muscles) and the portion of the optic nerve which is within or adjacent to the eyeball. An anterior ocular condition is a disease, ailment or condition which affects or which involves an anterior (i.e. front of the eye) ocular region or site, such as a periocular muscle, an eyelid or an eyeball tissue or fluid which is located anterior to the posterior wall of the lens capsule or ciliary muscles. Thus, an anterior ocular condition primarily affects or involves, the conjunctiva, the cornea, the conjunctiva, the anterior chamber, the iris, the posterior chamber (anterior to the retina but in posterior to the posterior wall of the lens capsule), the lens or the lens capsule and blood vessels and nerve which vascularize or innervate an anterior ocular region or site.
A condition of the posterior segment (posterior ocular condition) of the eye is a disease, ailment or condition which significantly affects or involves a tissue or cell type in a posterior ocular region or site (that is, in a position posterior to a plane through the posterior wall of the lens capsule), such as the accordingly located parts of the choroid or sclera, vitreous, vitreous chamber, retina, optic nerve (i.e. the optic disc), and blood vessels and nerves which vascularize or innervate a posterior ocular (or posterior segment) region or site.
Thus, a posterior ocular condition can include a disease, ailment or condition, such as for example, macular degeneration (such as non-exudative age-related macular degeneration and exudative age-related macular degeneration); choroidal neovascularization; acute macular neuroretinopathy; macular edema (such as cystoid macular edema and diabetic macular edema); Behcet's disease, retinal disorders, diabetic retinopathy (including proliferative diabetic retinopathy); retinal arterial occlusive disease; central retinal vein occlusion; uveitis (including intermediate and anterior uveitis); retinal detachment; ocular trauma which affects a posterior ocular site or location; a posterior ocular condition caused by or influenced by an ocular laser treatment; posterior ocular conditions caused by or influenced by a photodynamic therapy; photocoagulation; radiation retinopathy; epiretinal membrane disorders; branch retinal vein occlusion; anterior ischemic optic neuropathy; non-retinopathy diabetic retinal dysfunction, retinitis pigmentosa and glaucoma. Glaucoma can be considered a posterior ocular condition because a therapeutic goal can be to prevent the loss of or reduce the occurrence of loss of vision due to damage to or loss of retinal cells or optic nerve cells (i.e. neuroprotection). The infiltrative growth of new blood vessels can disrupt or destroy nervous tissue; thus the inhibition of angiogenesis can also be considered to provide protection to affected neurons.
Macular edema is a major cause of visual loss in patients, and can accompany a number of pathological conditions, including, without limitation, diabetes, central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). Although laser photocoagulation can reduce further vision loss in patients with diabetic macular edema (DME), vision that has already been decreased by macular edema through neural cell death usually does not improve appreciably by use of laser photocoagulation. Currently, there is no FDA (U.S. Food and Drug Administration) approved treatment for macular edema associated with CRVO. For macular edema associated with BRVO, grid laser photocoagulation may be an effective treatment for some patients.
Diabetic macular edema is characterized abnormal leakage of macromolecules, such as lipoproteins, from retinal capillaries into the extravascular space followed by an oncotic influx of water into the extravascular space. The leakage may be caused by or exacerbated by the growth of new blood vessels (angiogenesis). Abnormalities in the retinal pigment epithelium (RPE) may also cause or contribute to diabetic macular edema. These abnormalities can allow increased fluid from the choriocapillaries to enter the retina or they may decrease the normal efflux of fluid from the retina to the choriocapillaries. The breakdown of the blood-retina barrier at the level of the retinal capillaries and the retinal pigment epithelium may also be accompanied or caused by changes to tight junction proteins such as occluding. Antcliff R., et al Marshall J., The pathogenesis of edema in diabetic maculopathy, Semin Ophthalmol 1999; 14:223-232.
Macular edema from venous occlusive disease can result from thrombus formation at the lamina cribrosa or at an arteriovenous crossing. These changes can result in an increase in retinal capillary permeability and accompanying retinal edema. The increase in retinal capillary permeability and subsequent retinal edema can ensue from of a breakdown of the blood retina barrier mediated in part by vascular endothelial growth factor (VEGF), a 45 kD glycoprotein. It is known that VEGF can increase vascular permeability; possibly by increasing phosphorylation of tight junction proteins such as occludin and zonula occluden. Similarly, in human non-ocular disease states such as ascites, VEGF has been characterized as a potent vascular permeability factor (VPF).
Biochemically, VEGF is known to be a major contributor to the increase in the number of capillaries in tissue undergoing angiogenesis. Bovine capillary endothelial cells will proliferate and show signs of tube structures in vitro upon stimulation by VEGF. Upregulation of VEGF is a major component of the physiological response to exercise and its role in angiogenesis is suspected to be a possible treatment in vascular injuries.
VEGF causes an intracellular signaling cascade in endothelial cells. VEGF binding to VEGF receptor-2 (VEGFR-2) initiates a tyrosine kinase signaling cascade that stimulates the production of factors that variously stimulate vessel permeability (epithelial nitric oxide synthase; (eNOS), proliferation/survival (bFGE; basic fibroblast growth factor), migration (intercellular adhesion molecules (ICAMs); vascular cell adhesion molecules (VCAMs); matrix metalloproteases (MMPs)) and finally differentiation into mature blood vessels. As part of the angiogenic signaling cascade, NO (nitric oxide) is widely considered to be a major contributor to the angiogenic response because inhibition of NO significantly reduces the effects of angiogenic growth factors.
The normal human retina contains little or no VEGF; however, hypoxia causes upregulation of VEGF production. Disease states characterized by hypoxia-induced VEGF upregulation include, without limitation, CRVO and BRVO. This hypoxia induced upregulation of VEGF can be inhibited pharmacologically. Pe'er J. et al., Vascular endothelial growth factor upregulation in human central retinal vein occlusion, OPHTHALMOLOGY 1998; 105 412-416. It has been demonstrated that anti-VEGF antibodies can inhibit VEGF driven capillary endothelial cell proliferation. Thus, attenuation of the effects of VEGF introduces a rationale for treatment of macular edema from venous occlusive disease.
Additionally, overexpression of VEGF causes increased permeability in blood vessels in addition to stimulating angiogenesis. In “wet” or exudative macular degeneration, VEGF causes proliferation of capillaries into the retina. Since the increase in angiogenesis also causes edema, blood and other retinal fluids leak into the retina causing loss of vision. A novel treatment for macular degeneration is to use a VEGF inhibiting aptamer, or other VEGF-inhibiting compound, such as a TKI, to stop the main signaling cascade for angiogenesis, thereby preventing these symptoms.
European patent application 244 178 A2 (Keller) discloses intravitreal injection of an aqueous solution of dexamethasone, a steroid, and a hyaluronic acid (HA). Einmahl S. et al, Evaluation of a novel biomaterial in the suprachoroidal space of the rabbit eye, INVEST OPHTHAL & VIS SCI 43(5); 1533-1539 (2002) discusses injection of a poly(ortho ester) into the suprachoroidal space, and Einmahl S. et al, Therapeutic applications of viscous and injectable poly(ortho esters), ADV DRUG DEL REV 53 (2001) 45-73, discloses that a poly ortho ester polymer containing fluorouracil markedly degrades five days after intravitreal administration. European Patent Publication EP 0 244 178 describes HA compositions for intraocular injection containing antibiotics or anti-inflammatory agents. Della Valle et al., U.S. Pat. No. 5,166,331 discusses purification of different fractions of HA for use as a substitute for intraocular fluids and as a topical ophthalmic drug carrier.